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  2. Asterism (gemology) - Wikipedia

    en.wikipedia.org/wiki/Asterism_(gemology)

    The star-effect may be also caused by the inclusions of hematite. In black star sapphire hematite needles formed parallel to the faces of the second order prism produce asterism. Some star sapphires from Thailand contain both hematite and rutile needles forming a 12-ray star. [3] Star-stones were formerly regarded with much superstition. [1]

  3. Star sapphire - Wikipedia

    en.wikipedia.org/wiki/Star_sapphire

    Star sapphire or Star Sapphire may refer to: Star sapphire, a type of sapphire gemstone that exhibits a star-like reflection of light (an asterism) The Armstrong Siddeley Star Sapphire, a British car manufactured from 1958 to 1960; Star Sapphire (DC Comics character), the name of several fictional supervillains in DC Comics publications

  4. Sapphire - Wikipedia

    en.wikipedia.org/wiki/Sapphire

    A star sapphire is a type of sapphire that exhibits a star-like phenomenon known as asterism; red stones are known as "star rubies". Star sapphires contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"-shaped pattern when viewed with a single overhead light source.

  5. Black Star sapphire - Wikipedia

    en.wikipedia.org/wiki/Black_Star_sapphire

    Black star sapphire, also known as 'natural star sapphire' is a type of corundum (aluminum oxide). It is usually cut into a dome shape to show a star feature. If it is cut with a flat or almost flat face, then a golden colour is revealed. The chemical composition and features for black star were analyzed in the Journal of Gemmology. [citation ...

  6. Star of India (gem) - Wikipedia

    en.wikipedia.org/wiki/Star_of_India_(gem)

    Star of India. The Star of India is a 563.35-carat (112.67 g) star sapphire, one of the largest such gems in the world. [1] [a] It is almost flawless and is unusual in that it has stars on both sides of the stone. The greyish-blue gem was mined in Sri Lanka [3] and is housed in the American Museum of Natural History in New York City.

  7. Lapidary (text) - Wikipedia

    en.wikipedia.org/wiki/Lapidary_(text)

    Title page of a printed lapidary by Conrad Gessner of 1565. A lapidary is a text in verse or prose, often a whole book, that describes the physical properties and metaphysical virtues of precious and semi-precious stones, that is to say, a work on gemology. [1]

  8. Sapphirine - Wikipedia

    en.wikipedia.org/wiki/Sapphirine

    Sapphirine is a rare mineral, a silicate of magnesium and aluminium, with the chemical formula (Mg,Al) 8 (Al,Si) 6 O 20 (with iron as a major impurity). Named for its sapphire-like colour, sapphirine is primarily of interest to researchers and collectors: well-formed crystals are treasured and occasionally cut into gemstones.

  9. Lindy effect - Wikipedia

    en.wikipedia.org/wiki/Lindy_effect

    The Lindy effect (also known as Lindy's law [1]) is a theorized phenomenon by which the future life expectancy of some non-perishable things, like a technology or an idea, is proportional to their current age. Thus, the Lindy effect proposes the longer a period something has survived to exist or be used in the present, the longer its remaining ...